Clamping device



Sept. 20, 1966 v. J. HOLOPAINEN 3,273,729

CLAMPING DEVICE Filed Jan. 4, 1965 3 Sheets-Sheet 1 34 44 o' F/G.4

SePt- 20, 1966 v. J. HOLOPAINEN 3,273,729

CLAMPING DEVICE Filed Jan. 4, 1965 2 Sheets-@heet 2 VA/NO J. HOLOPA/NE N INVENTOR United States Patent O 3,273,729 CLAMPING DEVICE Vaino J. Holopainen, East Sullivan, N.H., assignor to Channel Construction, Inc., East Sullivan, N.H., a corporation of New Hampshire Filed Jan. 4, 1965, Ser. No. 423,188 Claims. (Cl. 214-138) This invention relates to a clamping device and, more particularly, to appa-ratus arranged to grasp objects and to move or transport them to a different location.

Dur-ing the last rfew years, a number of devices have been evolved which are mounted on tractors to permit the excavation of earth and the lifting and moving of materials. Among these is the so-called backhoe which, by using articulated arms and hydraulic cylinders, is capable of rather sophisticated movement in digging and grading. A backhoe operates satisfactorily Awhen it is dealing with particulate material but, when one attempts to move large objects, such as stones, logs, and the like with it, considerable difficulty is encountered. Although, in the past, such excavating equipment as the clam bucket and the like have been .used to move large stones and objects of a similar nature, excavating devices of that type are extremely expensive and, in most cases, hard to install. Furthermore, they are suspended by cables, so that positive control of location and operation is not possible. These and other diffculties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding objectl of the invention to provide a clamping device capable of grasping and lifting an object and moving it to another location.

Another object of this invention is the provision of a clamping device which can be mounted on a vehicle for grasping and lifting an object and transporting it to a different location.

A further object of the present invention is the provision of a clamping device which may be used with conventional hydraulic excavating equipment to grasp and lift objects.

It is another object of the instant invention to provide a clamping device which is positive and secure in nature and which makes use of existing equipment in producing an effective transport apparatus. l It is a further object of the invention to provide a clamping device which is simple in operation, which is inexpensive to manufacture, which is rugged in construction, and which is capable of a long life of useful service with a minimum of maintenance.

A still further object of this invention is the provision of a clamping device constituting an attachment for use with an articulated hydraulic backhoe. With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts 'set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to one of its structural forms as illustrated by the accompanying drawings in which:

FIG. 1 is a side view of a clamping device embodying the principles of the present invention;

FIG. 2 -is a somewhat enlarged view showing the details of the apparatus while in use;

FIG. 3 is a perspective view of the apparatus showing the elements in inoperative position; and

FIG. 4 is a schematic hydraulic diagram showing the relationships in the control elements of the device.

Referring first to FIG. l, wherein are best shown the general features of the invention, the clamping device, indicated generally by the reference numeral 10, is shown 3,273,729 Patented Svept. 20, 1966 "ice in use `with a vehicle 11 which, for the purposes ofillustration, is pictured as a four-wheel tractor. The vehicle is provided with a frontend loader 12 which, on occasion, may carry ballast. Fastened to the other end of the vehicle is a support 13 from which extend stabilizing arms 14. These arms are pivotally attached to the support and are moved from upper to lower positions by hydraulic actuators (not shown). Also attached to the support is a boom 15 which is Ipivotally attached to the support 13 for movement about a horizontal axis under the impetus of a boom cylinder .16. The boom 15 is also attached to the support 13 for pivoting about a vertical axis under the impetus of a hydraulic swing cylinder (not shown). Attached adjacent the outer end of the boom `15 is a dipper stick 17 which is hinged vat one end for swinging motion about a horizontal axis under the impetus of a dipper stick cylinder 18 (see FIG. 2). Pivotally attached to the other end of the dipper stick 17 is a bucket 19 -whose hinged action takes place through a bucket cylinder 21. Pivoted to the dipper stick 17 about the same pivot as the bucket 19 is an arm 22 which in the drawing is shown las grasping'an object, such as a rock 23, under the imeptus of a linear actuator such as an arm cylinder 24. This cylinder is attached at one end to the intermediate portion of the arm 22 and is pivotally attached at the other end to an intermediate portion of the dipper stick 17.

Referring to FIG. 2, the object being grasped is a log 25 which is normally a very difficult object to grasp and to handle. The arm 22 is provided with a bifurcation defining a right extension `26 and a left extension 27, both hingedly mounted on the pivot pin 28 whichis used to attach the bucket 19` to the lower end of the dipper stick 17 The portion of the arm 22 away from the pivot pin 28 is providedwith a relatively narrow web 29 which is ybent at its lower end into a hook or tooth. Extending from the Iweb 29 are flanges 31 and 32 which are also formed at the lower end with hooked or pointed portions to assist in forming a tooth with the lower bent portion of the web 29. In place of the tooth, the arm may be provided with a semi-rigid pad or the like; the form and nature of this contact portion may be varied to suit type of material usually handled by the clamp. Between the fiangcs 31 and 32 is pivotally mounted a block 33 which is mounted on the free end of a piston rod 34 forming part of the arm cylinder 24. Extending from the edge of the dipper stock 17 which faces toward the boom 15 are two flanges 35 and y36 through which extends a pivot pin 37 on which the cylinder 24 is pivotally mounted.

FIG. 3 shows the condition of the equipment in relaxed condition, lparticularly with the arm 22 drawn up against the dipper stick in a retracted position so that it does not interfere with the use of the bucket and the apparatus for conventional digging operations. In this condition, the flanges 31 and 32 of the arm embrace the cylinder 24 and protect it, while the web 29 serves the same purpose.

FIG. 4 shows the hydraulic circuitry associated with the bucket cylinder 21 and the arm cylinder 24. A conventional hydraulic pump 38 .receives hydraulic fluid from ia sump 39 and is connected by a conduit 41 to an input pressure port 42 of a valve 43. The valve has a housing 44 through which the port 42 passes. In the bore of the lhousing is slidably carried a spindle 45. The housing is provided with two output ports 46 and 47. The output port 46 is connected by a pressure line 48 to the cylinders 21 and 24, while these same cylinders are connected by a drain line 49 to the port 47. The valve 43 is also provided with drain ports 51 and 52 which are connected by lines 53 and 54, respectively, back to the sump 39. A spring 55 extends between the bottom of the housing 44 and the spindle 45 to maintain the valve in the condition shown in the, drawing with the port 42 operatively connected to the pressure port 46 and the port 47 operatively connected to the drain port 52. An operating handle 55 is hingedly attached to the top of the valve housing and its inner end contacts the spindle 45 to press it downwardly (against the pressure of the spring 45) to a secondary position in which the port 46 is connected to the drain port 51 and the pressure port 42 is connected to the port 47 for reverse operation of the cylinders 21 and 24. The pressure line 48 is connected to the tops of the cylinders 21 and 24 by branch lines 56 land 57, respectively. In the branch 57 is located a shut-oi valve 58 which, for the purposes of illustration, is shown as a ball valve. In the branch line 57 is also located a combination check valve land restrictor 59 which has the function of permitting oil to pass into the top of the cylinder from the pressure line 48 in a small regulated amount for downward movement of the piston rod 34. However,

when the pressure oil is connected to the bottom of the cylinder 24, the oil on top of the piston is allowed to be pushed out through the check valve relatively easily. It should be noted that the bucket 19 consists of two sides, 62 and 63 between which extends a cutting edge 61. This cutting edge is provided with replaceable teeth 64 in the usual manner.

The operation of the invention will now be readily understood in view of the above description. When it is desired to pick up an object, such'as the log 25, the arm 22, and the bucket 19 are in open or spaced-apart condition, somewhat similar to what is shown in FIG. 3. The boom 15 and the dipper stick 17 are operated to bring the bucket cutting edge 61 on one` side of the log 25 and the [arm 22 on the other side. The valve 43 is placed in the condition shown in'FIG. 4 so that pressure oil passes from the pump 38 through the line 41 and the port 42 to the port 46 and the pressure line 48. This pressure oil passes directly into the top of the cylinder 21, thus causing the bucket to move toward the arm. At the same time, pressure oil passes Ithrough the check valve and restrictor 59 and the valve l58 (now in open position) into the cylinder 24 so that the piston rod 34 is advanced, thus pressing Ithe arm 22 toward the bucket. Eventually, the full hydraulic pressure on the cylinders 21 and 24 will cause the log 25 to be grasped between the bucket 19 and the arm 22. The teeth 64 on the cutting edge of the bucket 19 and the tooth formed by the bottom of the web and the flanges 31 and 32 serve to extend under the log and prevent it from falling from between the bucket and the arm.

This same system is used in grasping la rock or any other large object; the teeth 64 on the bucket are used to assist in grasping the object while the tooth formed at the bottom of the arm 22 serves the same purpose. However, it should be noted that whilel the cutting edge 61 provides a broad support for the object being lifted, the arm 22 provides a relatively narrow pressure point against it. This is helpful, since it results, in most cases, in 1a three-point suspension of the object which means greater stability of lifting. Because of the swinging unotion of the boom 15, its adjustment about the horizontal laxis, and the swinging motion of the dipper stick 17, it is possible to grasp an object which has an indeterminate relationship to the position of the vehicle 11 and to place it in another position to one side or rearwardly of the vehicle. The dipper stick and boom and their various motions give a complete latitude of rnotion to the clamping device. If the object being clamped and lifted is very heavy, the stabilizing arms 14 and their engagement with the ground prevent the vehicle 19 from tipping over. The stabilizing arms operate as a fulcrum so that the entire weight of thevehicle (and any ballast that may be in the front end loader 12) balance any weight that may exist in the clamping device, in accordance with the wellknown principles of physics.V t

It should be noted that, because of the restrictor 59, the arm 22 operates at a slower speed than the bucket 19. At times, it may be desirable to lock the arm 22 in a given position; for that purpose, it is possible to trap the' oil in the upper part of the cylinder by closing the valve 58. At that time, the only motion that takes place is through the cylinder 21. In that event, the bucket 19 moves :at its normal rate. When the arm is being returned lto its retracted position (las shown in FIG. 3), pressure oil is admitted to the bottom of the cylinder 24 by the actuation of the operating'handle 55. The oil in the top of the cylinder 24 is pressed at a fairly rapid rate through the check valve and restrictor 59, since this element is manufactured to present Very little resistance to the flow of oil in that particular direction. It will be understood that for the purpose of simplifying the description, the valve 43 is shown as having only two functional positions for the two directions of movement of the cylinders; as a practical matter, however, it would normally be provided with a neutral position in which no oil would move to the cylinders.

It can be seen that by use of the present device it is possible to handle any type of irregular object by use of a more or less conventional articulated backhoe mechanism. Nevertheless, when the arm 22 is not in use in grasping an object, the rest of the apparatus including the bucket 19, the boom 15, and the dipper stick 17 may be used as a conventional backhoe lwithout the arm and its associated mechanism inhibiting such operation. The `arm 22 is formed to protect the cylinder 24 and, particularly, that portion of the cylinder from which the piston rod 34 emerges with its seals and so on. The piston rod, of course, must be kept free of scratches, if possible, so that the seals in the area of its emergence from the cylinder will not be cut and scored causing leakage. It can be seen that the present apparatus is relatively simple in construction and yet entirely operative to produce the function described. It will be understood that, `although the hydraulic system serving both the bucket cylinder 21 tand arm cylinder 24 is provided with a single Aow ,control valve 43 for simultaneous movement of the two cylinders, it is contemplated that, on occasion, it may be desirable to provide each cylinder with an independent control valve and circuits for separate and independent movement.

It is obvious that minor changes may be marde in the form and construction of the invention without departing from ythe material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is :claimed as new and `desired to secure by Letters Patent 1. Clamping device for use with a vehicle, comprising (a) a dipper stick having an actuating cylinder for changing its aspect relative to the vehicle,

(b) a bucket pivotally attached to one end of the dipper stick, and an actuating cylinder for changing the aspect of the bucket relative to the dipper stick,

(c) a clamping arm pivotally mounted adjacent the Ibucket for hinged movement about substantially the same axis as the bucket, and

(d) an actuating cylinder operatively connected between the dipper stick and the arm to bring about pivotal movement of the bucket and arm toward and away from onev another.

2. Clamping device for use with a vehicle, comprising (a) a support adapted to be attached to a vehicle,

(b) stabilizing arms atached to the support and adapted to engage the ground,

(c) a boom mounted on the support and pivotal about a vertical axis and a horizontal axis,

` (d) a dipper stick pivotally attached to the boom and having a bucket pivotally attached to one end, and

having an actuating cylinder for changing its aspect relative to the boom,

(e) a clamping arm pivotally mounted adjacent the bucket for hinged movement about substantially the same axis as the bucket, and 5 (f) hydraulic actuators connected between the dipper stick on the one hand and the bucket and the arm on the other hand to bring about pivotal movement toward and away from one another.

3. Clamping7 device as recited in claim 2, wherein the 10 bucket consists of two sides joined by a cutting edge, the arm having teeth at its outer end located adjacent the cutting edge of the bucket midway between the sides.

4. Clamping device as recited in claim 2, wherein a hydraulic actuator is provided for the bucket, wherein a 15 hydraulic `actuator is provided for the arm, and wherein a valve located on the support controls the flow of operating iluid to and from the actuators.

5. Clamping device, comprising (a) a support adapted to be attached to a vehicle, 20

(b) stabilizing arms attached to the support and adapted to engage the ground,

(c) a boom mounted on the support and pivotal about a vertical axis and a horizontal axis,

(d) a clipper stick pivotally attached to the boom and 25 having a bucket pivotally attached to one end,

(e) an arm pivotally mounted adjacent the bucket for hinged movement about substantially the same axis as the bucket, and

(f) hydraulic actuators associated with the bucket and arm to bring about pivotal movement toward and away from one another, one actuator being provided for the bucket and the other actuator being provided for the arm, a valve located on the support controlling the flow of operating fluid to and away from the actuators, single pressure and drain lines extending from the valve to serve both actuators, separate branch lines extending from the pressure line to the bucket actuator and from the pressure line to the arm actuator, a shut-01T valve being mounted in the branch line to the arm actuator, and a check valve and restrictor being mounted on the branch line to the arm actuator.

References Cited by the Examiner UNITED STATES PATENTS 2,848,125 8/1958 Irvine 214-147 X 3,057,496 10/1962 Garske 214-145 X 3,143,227 8/1964 Wiemann 214-138 3,156,368 11/1964 Schutte 214-147 FOREIGN PATENTS 575,948 5/1959 Canada. 140,176 4/ 1953 Sweden.

HUGO O. SCHULZ, Primary Examiner. 

1. CLAMPING DEVICE FOR USE WITH A VEHICLE, COMPRISING (A) A DIPPER STICK HAVING AN ACTUATING CYLINDER FOR CHANGING ITS ASPECT RELATIVE TO THE VEHICLE, (B) A BUCKET PIVOTALLY ATTACHED TO ONE END OF THE DIPPER STICK, AND AN ACTUATING CYLINDER FOR CHANGING THE ASPECT OF THE BUCKET RELATIVE TO THE DIPPER STICK, (C) A CLAMPING ARM PIVOTALLY MOUNTED ADJACENT THE BUCKET FOR HINGED MOVEMENT ABOUT SUBSTANTIALLY THE SAME AXIS AS THE BUCKET, AND (D) AN ACTUATING CYLINDER OPERATIVELY CONNECTED BETWEEN THE DIPPER STICK AND THE ARM TO BRING ABOUT PIVOTAL MOVEMENT OF THE BUCKET AND ARM TOWARD AND AWAY FROM ONE ANOTHER. 